Settlement house (1947) in timber frame construction - is renovation worthwhile?

To judge that, you have far too little information. It is true that in the post-war years, buildings were often constructed cheaply. But not necessarily poorly. It is by no means certain that there is mold or pests. Our house is a timber frame with bricks from 1921 and has none of that. It is a very solid building structure that has stood firm for 99 years. If the neighbors have renovated, definitely talk to them. They have the same house as you, which is fantastic! You really couldn’t find out better what to expect. The rest can be told to you by an expert on site. Here on the internet, it’s just crystal ball reading.